A surface-emission laser diode (surface-emission semiconductor laser) is a laser diode that emits light in a vertical direction to the substrate and is used for civil purposes, such as optical source of optical telecommunication including optical interconnection, optical source of optical pickup devices, optical source of image forming apparatuses, and the like.    Patent Reference 1 Japanese Laid-Open Patent Application 2002-164621    Patent Reference 2 Japanese Laid-Open Patent Application 9-107153 official gazette    Patent Reference 3 Japanese Laid-Open Patent Application 2001-60739    Patent Reference 4 Japanese Laid Open Patent Application 2001-168461    Non-patent Reference 1 IEEE Photonics Technology Letters, Vol, 10, No. 12, pp. 1676-1678, 1998 (Tokyo Institute of Technology)    Non-patent Reference 2 IEEE Photonics Technology Letters, Vol. 12, No. 6, pp. 603-605, 2000 (Wisconsin Univ.)